Apparatus for recording or reproducing sound



I Jan. 3, 1933.

R. D. GIVEN ET AL APPARATUS FOR RECORDING 0R REPRODUCING SOUND Filed Jan. 27, 1931 em e rww n r r t e nD f nm d. .m 1mm w T Patented Jan. 3, 1933 UNITED STATES PATENT OFFICE RALPH 1). Given, or LEAMINGTON sPA, AND HAROLD F. JEFFERSON, or. RUGBY, ENGLAND, 'AssIeNoRs T GENERAL ELECTRIC coMPANY, A coaPonA'rIoN or NEW YORK APPARATUS FOR RECORDING QR BEPBODUCING SOUND Application filed January 27, 1931, Serial No. 511,594, and in Great Britain January Our invention relates to. apparatus for recording or reproducing sound and particularly to the driving means for such sound record apparatus. It is the object of our invention to provide an improved sound record driving means whereby fluctuations in the speed of the driving sourcemay be prevented from being transmitted to the record.

I WVe have chosen to. illustrate our invention ance therewith the turntable, which is conas applied to a phonograph and in accordstructed to constitute ii -effect an inertia member or flywheel, is driven through a worm and worm gear and the worm is mount- I closes the worm drive.

ed so as to have a limited axial yielding movement but is resiliently restrained from such movement. To prevent hunting we provide damping means which is associated with the worm. The damping means preferably is of the dash-pot type using oil and is located in the same oil containing casing which en- Our invention will from the followingdescriptiontaken in connection with the accompanying drawing, and its scope will be pointed out'in the appended claims.

Referring to the drawing,,Fig. 1 is a view showing the complete apparatus, and-Fig. 2 shows a portion thereof which is partly a sectional view and is drawn to-a larger'scale.

From the drawing it will be seen that the turntable spindle 1 is driven by means of the worm-wheel 2 secured to the spindle and meshing with the worm 3 which in turn is secured to the shaft 4. This shaft is journalled in the enclosing casing 5 and has a limited amount of longitudinal movement. The movement ofv shaft 4 is controlled by means of the springs 6 and 7 which embrace the rod 8 secured to the arms 9 and 10 which are loosely mounted on shaft 4. Arm 9 is so secured to shaft 4 and rod 8 that any longitudinal movement of the shaft is communicated through arm 9 to rod 8. Each spring engages at one end the arm 11 attached to the enclosing casing 5 .and at their opposite ends, the springs are a'djustably connected with the rod 8 by means of adjusting nuts 12 and 13. The turntable 14 is be better understood so, i930.

shown formed as a relatively heavy flywheel whereby irregularities in its speed are substantially avoided and consequently a sadden acceleration or deceleration of the speed of rotation of the shaft 4 causes the shaft to move longitudinally under the control of the springs 6; and 7 which springs tend to return it to its normal position. The longitudinal movement of shaft 4 is permitted by the interposition of the flexible coupling 15 (see teriaL. The elasticity of the diaphragm tends toprevent the transmission of any vibrati'on in the shaft 16 to the shaft 4 as Well as permitting axial movement of the shaft 4. In order to prevent hunting of the shaft 4,

we have provided a damping arrangement which preferably is of the dash-pot type. This is shown as comprising the piston 20attached to the rod 21 which is secured to the lower end of the arm 9, the piston 20 working in the cylinder 22 which is filled with a suitable fluid such, for example, as oil, a path being provided betweeneach end of the cylinder through the transverse ports 23 and the longitudinal port 24. In the port 24 there is provided the adjustable valve screw 25 which enables the port 24 to. be throttled to give the exact amount of damping required. In order to prevent loss of oil the dash-pot cylinder 22 is immersed in the oil contained in the casing 5 which provides the'necessary lubrication for the worm drive for the turntable. Light spring ball valves 26 are provided to permit automatic replenishment of any oil lost from the dash pot.

The turntable may be resiliently mounted by making the base pad 28 of flexible material such, for example, as cork. The cork pad 28 may in turn be seated on the base plate 29 which if desired may be provided with an adin said casing and cooperating with another 1ustable mounting to permit of the alignment portion of sa1d arm.

of the shafts 4 and 16. In witness whereof, we have hereunto set It 1s to be noted that while we have shown our hands this 12th day of January, 1931. 5 and described the gears 2 and 3 as a worm RALPH D. GIVEN. 73

wh el and worm respectively, any other form HAROLD F. JEFFERSON. of gearing may be used, such, for example,

as spiral gears, wherein the driving force has a component in the axial direction of one of the gears and the axial movement of this 70 gear is resiliently restrained.

We have chosen the particular embodiment described above as illustrative of our invention and it will be apparent that various other modifications may be made without depart- :3-

ing from the spirit and scope of our invention, which modifications we aim to cover by the appended claims.

What we claim as new and desire to secure by Letters Patent of the United States, is,- 53

1. Pho'nograph driving apparatus comprising a turntable adapted to support a record disk, a worm gear connected therewith, a worm meshing with the worm gear, driving means for the worm, means for supporting C3 the worm to permit a limited axial movement thereof, means for resiliently holding the worm in a predetermined position, and means for damping axial movements of the worm.

2. Phonograph driving apparatus comprising a turntable adapted to support a record disk, a worm gear connected therewith, a driving worm meshing with the worm gear mounted to have limited axial movement, lco

means for resiliently opposing said movement, an oil retaining casing for said gear,. and an oil dash pot device connected with said worm and arranged to operate with the oil in said casing; 10.)

3; Phonograph driving apparatus comprising a turntable adapted to support a record disk, a worm gear connected therewith, an enclosing casing therefor, a worm shaft journalled therein, a worm on said shaft in mesh with said worm gear and having a limited axial movement, a rod slidably mounted in said casing and connected with said worm, and springs associated with said casing and said rod for yieldably maintaining the worm in a predetermined position.

4. Phonograph driving apparatus comprising a turntable adapted to support a record 55 disk, a worm gear connected therewith, a 123 worm meshing with the worm gear, an oil retaining enclosing casing for said gear and worm, a drive shaft secured to said worm and journalled for rotary and axial movement in 50 said casing, a motor having a flexible connec- 125 tion with said shaft, an arm rotatablymounted on said shaft, springs cooperating with one portion of said arm for maintaining the shaft and worm in a predetermined axial po- 65 sition, and an oil dash pot arranged in the oil 

